ARM: OMAP2+: pm33xx: Add support for rtc+ddr in self refresh mode

Add support for rtc+ddr in self refresh mode. Add addtional
pm hooks for save/restore and rtc suspend/resume.
Signed-off-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/mach-omap2/pm33xx-core.c

@@ -10,6 +10,12 @@
 #include <asm/suspend.h>
 #include <linux/errno.h>
 #include <linux/platform_data/pm33xx.h>
+#include <linux/clk.h>
+#include <linux/platform_data/gpio-omap.h>
+#include <linux/pinctrl/pinmux.h>
+#include <linux/wkup_m3_ipc.h>
+#include <linux/of.h>
+#include <linux/rtc.h>
 
 #include "cm33xx.h"
 #include "common.h"
@@ -38,6 +44,29 @@ static int am43xx_map_scu(void)
 	return 0;
 }
 
+static int am33xx_check_off_mode_enable(void)
+{
+	if (enable_off_mode)
+		pr_warn("WARNING: This platform does not support off-mode, entering DeepSleep suspend.\n");
+
+	/* off mode not supported on am335x so return 0 always */
+	return 0;
+}
+
+static int am43xx_check_off_mode_enable(void)
+{
+	/*
+	 * Check for am437x-gp-evm which has the right Hardware design to
+	 * support this mode reliably.
+	 */
+	if (of_machine_is_compatible("ti,am437x-gp-evm") && enable_off_mode)
+		return enable_off_mode;
+	else if (enable_off_mode)
+		pr_warn("WARNING: This platform does not support off-mode, entering DeepSleep suspend.\n");
+
+	return 0;
+}
+
 static int amx3_common_init(void)
 {
 	gfx_pwrdm = pwrdm_lookup("gfx_pwrdm");
@@ -139,6 +168,8 @@ static int am43xx_suspend(unsigned int state, int (*fn)(unsigned long),
 	scu_power_mode(scu_base, SCU_PM_POWEROFF);
 	ret = cpu_suspend(args, fn);
 	scu_power_mode(scu_base, SCU_PM_NORMAL);
+
+	if (!am43xx_check_off_mode_enable())
 		amx3_post_suspend_common();
 
 	return ret;
@@ -161,10 +192,48 @@ void __iomem *am43xx_get_rtc_base_addr(void)
 	return omap_hwmod_get_mpu_rt_va(rtc_oh);
 }
 
+static void am43xx_save_context(void)
+{
+}
+
+static void am33xx_save_context(void)
+{
+	omap_intc_save_context();
+}
+
+static void am33xx_restore_context(void)
+{
+	omap_intc_restore_context();
+}
+
+static void am43xx_restore_context(void)
+{
+	/*
+	 * HACK: restore dpll_per_clkdcoldo register contents, to avoid
+	 * breaking suspend-resume
+	 */
+	writel_relaxed(0x0, AM33XX_L4_WK_IO_ADDRESS(0x44df2e14));
+}
+
+static void am43xx_prepare_rtc_suspend(void)
+{
+	omap_hwmod_enable(rtc_oh);
+}
+
+static void am43xx_prepare_rtc_resume(void)
+{
+	omap_hwmod_idle(rtc_oh);
+}
+
 static struct am33xx_pm_platform_data am33xx_ops = {
 	.init = am33xx_suspend_init,
 	.soc_suspend = am33xx_suspend,
 	.get_sram_addrs = amx3_get_sram_addrs,
+	.save_context = am33xx_save_context,
+	.restore_context = am33xx_restore_context,
+	.prepare_rtc_suspend = am43xx_prepare_rtc_suspend,
+	.prepare_rtc_resume = am43xx_prepare_rtc_resume,
+	.check_off_mode_enable = am33xx_check_off_mode_enable,
 	.get_rtc_base_addr = am43xx_get_rtc_base_addr,
 };
 
@@ -172,6 +241,11 @@ static struct am33xx_pm_platform_data am43xx_ops = {
 	.init = am43xx_suspend_init,
 	.soc_suspend = am43xx_suspend,
 	.get_sram_addrs = amx3_get_sram_addrs,
+	.save_context = am43xx_save_context,
+	.restore_context = am43xx_restore_context,
+	.prepare_rtc_suspend = am43xx_prepare_rtc_suspend,
+	.prepare_rtc_resume = am43xx_prepare_rtc_resume,
+	.check_off_mode_enable = am43xx_check_off_mode_enable,
 	.get_rtc_base_addr = am43xx_get_rtc_base_addr,
 };
 

include/linux/platform_data/pm33xx.h

@@ -51,6 +51,11 @@ struct am33xx_pm_platform_data {
 			       unsigned long args);
 	struct  am33xx_pm_sram_addr *(*get_sram_addrs)(void);
 	void __iomem *(*get_rtc_base_addr)(void);
+	void (*save_context)(void);
+	void (*restore_context)(void);
+	void (*prepare_rtc_suspend)(void);
+	void (*prepare_rtc_resume)(void);
+	int (*check_off_mode_enable)(void);
 };
 
 struct am33xx_pm_sram_data {